Building boards, and more particularly, ceiling boards, have conventionally been made by wet laying processes and the boards resulting from such processes have had to be sawed in order to yield product having a required dimension. The use of saws is undesirable for a number of reasons. One reason is that a substantial amount of dust is created during the sawing process, thereby leading to fire hazards, and air pollution and health hazards. A second reason is that difficulty has often been encountered in maintaining saw registration so as to consistently provide product having exact dimensions and exact geometry (e.g., squareness).
Recently, U.S. Pat. No. 4,476,175 disclosed groove molded building boards which were prepared such that the use of saws could be avoided. Each board was provided with grooved lines of demarcation which permitted the removal of edge scrap, and also permitted the boards to be easily divided into individual board segments. However, no apparatus existed for the processing of such boards, and the separation of the scrap and the dividing of the boards into individual pieces had to be accomplished by hand.